The present invention relates to an optical element. More particularly, the present invention relates to a hard coat composition, a primer composition in the surface of the optical element, a surface processing technology such as a reflection prevention film and the like and a dyeing method. The present invention is preferable for an optical part (optical element) of an organic glass base material having particularly a high refractive index.
As used herein, the term xe2x80x9coptical elementxe2x80x9d refers to a concept which includes, but not limited to, original optical elements such as a lens for glasses, a lens for camera, a lens for microscope, a lens for telescope, a lens for binocular, a reflecting mirror, a prism and the like, also includes a filter, a cover for a lighting fitting and the like.
In the following description, a lens for glasses (optical lens) will be mainly exemplified and described, but not limited to this.
In recent years, as a material of an optical lens, an organic glass has been popular among the people, which is lightly weighted, and excellent at shock resistance, having chromatophilia and easily processed comparing with an inorganic glass. Among these, an organic glass having a high refractive index, which is capable of thinning the thickness of lens (refractive index, around 1.60) has been widely used. However, in general, an organic glass has a lower abrasive resistance (resistance against scraping and damaging) compared with an inorganic glass, therefore, easily scraped and damaged. Hence, in general, a hard coat (silicone-based hardening film coating) is performed on the surface of the organic glass base material (hereinafter, it may be referred to only as xe2x80x9cbase materialxe2x80x9d). Furthermore, in a lens for glasses, from the reasons such as the esthetic reason and the like, an inorganic reflection prevention film is often formed by dry plating such as vapor deposition and the like of inorganic substances.
However, as described above, a lens to which both a hard coat and an inorganic reflection prevention film have been provided had a non-conformity of shock resistance being inferior. Hence, in order to enhance the shock resistance, a variety of technical concepts in which between the base material and the hard coat, a primer layer consisted of polyurethane based coating (mainly, urethane base thermoplastic elastomer (hereinafter, referred to as xe2x80x9cTPUxe2x80x9d) is made coating film formation element) is intervened have been proposed.
Then, it is necessary to secure the refractive index similar to the base material in each layer in order to prevent the optical interference of a lens in the case where the above-described hard coat layer and primer layer are laminated on a base material having a high refractive index.
The present inventors have previously proposed a primer composition which prevents the occurrence of optical interference even if the base material has relatively a high refractive index (see Japanese Unexamined Patent Publication No. Hei 6-82694) and a hard coat composition having a high refractive index (see Japanese Patent No. 2577670), and one portion of these has been developed to put to practical use.
However, as a trend in recent years, the fashionability has been considered as a more important factor, as the needs which the thickness of lens edge face has to be thinner are enhanced, a super high refractive organic lens having a higher refractive index (refractive index 1.70) has been commercially available in the optical industry.
Then, it has been found that it is difficult to suppress the light interference in the case where a hard coat composition described in the above-described Japanese Patent No. 2577670 is coated on the above-described lens having a super high refractive index.
Moreover, it has been found that after the long term of usage of lens has been passed, the hard coat layer causes the blackening phenomenon due to the ultraviolet ray to occur and esthetic aspect is damaged. This blackening phenomenon is estimated on the basis of iron oxide in the iron oxide/titanium oxide complex oxide particle which has been used as a hard coat ingredient.
Furthermore, it has been found that the primer composition described in the above-described Japanese Unexamined Patent Publication No. Hei 6-82694 lowers the heat resistance of the base material, and the material is easily non-uniform within the layer, therefore, cloudiness due to the irregular reflection of light is recognized.
On the other hand, the above-described material having a high refractive index is more difficult to dye comparing with a material having a lower refractive index. Therefore, in the immersion dyeing method in which the base material is immersed in an aqueous dye bath (aqueous solution) which uses disperse dye and the like, the problems listed below have been easily occurred.
It is difficult for an immersion dyeing method to perform a dyeing of a uniform and stable coloring to the base material. This is the reason why the dyeing property (dyeing speed and dyeing equilibrium) is easily influenced with the respective ingredient concentration of dye aqueous dispersion liquid (disperse dye, surfactant, dyeing promoter and the like) and variation of dyeing temperature, and further, the kind of an organic glass base material. Moreover, in the case where a higher concentration dyeing (dyeing property) is required, it needs to dye for a long time period. Moreover, since it is the dyeing in the low temperature and the dyeing property is not sufficient, fading in the coloring in the subsequent steps is significant, it is difficult to finish it in the desired coloring.
In order to solve the problem of the above-described immersion dyeing method, for example, a method of heating and transcribing the dye (migration) after the dye is sublimed at gaseous phase and the dyeing layer is formed on the surface of the glass surface (Japanese Unexamined Patent Publication No. Sho 56-159376 and the like), and a method of adhering the transcribed film which has been dyed on the surface of an organic glass base material and heating and transcribing (Japanese Unexamined Patent Publication No. 2000-17586 and the like) have been proposed.
However, in the former method, since the sublimation temperatures are different depending on the dyes, it is difficult to obtain the desired coloring, coloring concentration on and in the base material, and in the latter method, it is difficult to precisely adhere the transcription film on the curved surface and it is difficult to obtain a uniform without coloring variation on and in the base material.
The first object of the present invention is to provide a primer composition in which refractive index can be adjustable without lowering the heat resistance of the base material and the cloudiness due to the irregular reflection of light is slight as well as the similar characteristics (shock resistance, scraping and damaging resistance and the like) as the conventional primer composition can be conferred and an optic element utilizing the primer composition.
The second object of the present invention is to provide a hard coat composition which is capable of suppressing the optical interference with respect to a base material having a super high refractive index and is excellent at light resistance without damaging the esthetic aspect even if the optic part is used for a long term without occurring the blackening phenomenon due to the ultraviolet and an optical element utilizing the hard coat composition.
The third object of the present invention is to provide an organic glass optic element in which the adhesion with the hard coat layer, the scraping and damaging resistance and the heat resistance are excellent in an optic element having the above-described hard coat layer, and the foregoing organic glass optic element having a reflection prevention film having an excellent reflection prevention effect in the wide range of wavelengths and the foregoing reflection prevention film capable of being well colored in an interference color of green which is generally required for lens for glasses.
The fourth object of the present invention is to provide a composition for dyeing an organic glass capable of stably and well dyeing and further dyeing it to the required coloring and a method of dyeing an organic glass.
(1) The first invention achieves the above-described first object with a primer composition of the following constitution and a primer element consisted of the relevant primer composition.
A primer composition of the present invention is characterized in that it is a composition for forming a primer layer between an organic glass and a silicone based hardening coating film, and whole of or the main body of the primer layer forming polymer is a polyester based thermoplastic elastomer (ester based TPE).
It is desirable that the above-described primer composition contains a metal oxide particle as an optical interference control agent (refractive index preparation).
It is desirable that the above-described ester based TPE molar ratio of the hard segment and the soft segment is the former/the latter=30/70-90/10, and the relevant ester base TPE exhibits the characteristics of surfacial hardness (shore hardness D): 35-75 and bend elasticity: 40-800 MPa.
(2) The second invention achieves the above-described second object by an optic element having a hard coat layer consisted of a hard coat composition of the following constitution and the relevant hard coat composition.
A hard coat composition of the present invention is characterized in that hydrolysate of alkoxysilane consisted of trialkoxysilane as the main body containing monoepoxy organic group is made a matrix formation ingredient, and titania based metal oxide complex particle is made optic interference control agent (refractive index preparation), the titania based metal oxide complex particle is made consisted of TiO2 as the main body, SiO2 as the major sub-ingredient, and further, ZrO2 and K2O as a trace sub-ingredient.
For the above-described titania based metal oxide complex particle, it is desirable that its average particle diameter is made as 1-50 nm, its composition is made as satisfying the respective weight ratio of SiO2/TiO2=0.1900-0.2100, ZrO2/TiO2=0.0015-0.023, K2O/TiO2=0.0012-0.012, and the contents are made as 40-100 weight portions with respect to the total alkoxysilane 100 weight portions.
Moreover, it is desirable that trialkoxysilane containing monoepoxy organic group is consisted of one or more species selected from the group expressed by the following general formula (1):
General Formula (1) 
(where R1 represents H or CH3, R2 represents alkylene group having the number of carbon atoms of 1-4. R3 represents alkyl group having the number of carbon atoms of 1-4), or, from the group expressed by the following general formula (2):
General Formula (2) 
(where R1 represents alkylene group having the number of carbon atoms of 1-4 and R2 represents alkyl group having the number of carbon atoms of 1-4)
Furthermore, it is desirable that as alkoxysilane except for the foregoing trialkoxysilane containing monoepoxy organic group, tetraalkoxysilane indicated by the following general formula (3):
xe2x80x83Si (OR1)4xe2x80x83xe2x80x83
General Formula (3)
is used, and the content of the tetraalkoxysilane is made less than 20 wt % in the total alkoxysilane.
Moreover, it is desirable that it contains an organic metal compound as a hardening agent of the matrix formation ingredient, the relevant organic metal compound(s) of one or more species selected from the group of chelating compounds of Cr (III), Co (III), Fe (III), Zn (II), In (III), Zr (IV), Y (III), Sn, V, Al (III), Ti (II) with which a chelating agent selected from ethylenediamine-tetraacetic acid (EDTA), hexafluoroacetylacetone, trifluoroacetylacetone, acetyl acetone and methyl acetoacetate coordinates are used.
An organic glass base material to which a hard coat composition of the second invention is applied is preferably indicates 1.66 or more of the refractive index.
As an organic glass indicating more than 1.66 of the above-described refractive index, an organic glass obtained by polymerizing and reacting (1) active hydrogen compounds of one or more species selected from the group of polyol, polythiol and hydroxy compound having a mercapto group, and (2) one or more species selected from the group of polyisothiocyanate compound or isothiocyanate compound having an isocyanate group, or, an organic glass obtained by polymerizing and reacting episulfide compound having more than two pieces of structures indicated by the following general formula (4)and a ring-like frame:
General Formula (4) 
(where X represents S or O, and the number of pieces of S is more than 50% on average with respect to the total of S and O constituting three-membered ring)
(3) The third invention achieves the above-described object by further laminating a reflection prevention film layer of an inorganic substance based one of the following constitution on the above-described hard coat layer.
The configuration of the reflection prevention film is characterized in that as design center wavelength xcex is made as in the range of 450-550 nm, from the foregoing hard coat layer side, it has a multiple layers structure in which a medium refractive index layer having 0.19-0.29 xcex of an optic film thickness, a high refractive index layer having 0.42-0.58 xcex of an optic film thickness and a low refractive index layer having 0.19-0.29 xcex of an optic film thickness were in turn formed.
Furthermore, it is desirable that the medium refractive index layer and the high refractive index layer are consisted of equivalent layer using more than two layers whose refractive index are different, respectively.
It is desirable that in a method of forming the above-described reflection prevention film, before the formation of the reflection prevention film, the cleaning processingof the surface of the hardcoat layer is performed by an ion irradiation.
Then, it is desirable that among the reflection prevention films, the formation of at least high refractive index layer is performed by an ion beam assist method using vapor deposition technique.
(4) A composition for dyeing an organic glass and a method of dyeing an organic glass of the fourth invention achieves the foregoing fourth object.
A composition f or dyeing an organic glass of the fourth invention is characterized in that the dye is made as insoluble-in- water dye, dye carrier agent (sizing agent) is made as acryl based resin, the dye dissolving agent is made as an organic solvent in the range of 8-11 of SP value.
Then, it is desirable that the blending weight ratio of acryl based resin and insoluble-in-water dye is made as the former/the latter=60/40-5/95.
The above-described method of dyeing is characterized in that migration is performed to the base material to be dyed by attaching the above-described composition for dyeing on an organic glass base material or an organic glass base material equipped with a hard coat layer (hereinaf ter, referred to as xe2x80x9cbase material to be dyedxe2x80x9d) and by sublimating non-aqueous dye.